Metal–Organic Framework-Derived Hollow CoMn<sub>2</sub>O<sub>4</sub> Nanocube Catalysts for Deep Toluene Oxidation
Li Luo, Rui Huang, Wei Hu, Zhaoshi Yu, Zhixin Tang, Leqi Chen, Yunhuai Zhang, Dan Zhang, Peng Xiao
Abstract
Designing unique nanostructures and components for catalysts can promote the deep catalytic degradation of volatile organic compounds into CO2. Herein, a pyrolysis strategy for MOF-based oxides (Mn3[Co(CN)6]2·nH2O) was employed to successfully synthesize oxygen vacancy-enriched Mn–Co spinel oxides with hollow nanocube structures (denoted as MOF-CMO/400). Compared with CoMn2O4 nanoparticles prepared by the traditional precipitation method, MOF-CMO/400 presented a T90 of 209 °C for toluene catalytic oxidation, which was 38 °C lower than that of CoMn2O4 nanoparticles (247 °C). Especially in a high-temperature region, MOF-CMO/400 nanocubes possessed a narrower temperature range to achieve 100% toluene conversion than CoMn2O4 nanoparticles. The excellent catalytic activity of MOF-CMO/400 is mainly attributed to the three-dimensional hollow structure, more oxygen vacancy defects, longer Mn–O bonds, and abundant active oxygen species. Furthermore, MOF-CMO/400 nanocubes displayed good humidity resistance (above 5–10 vol % H2O). Therefore, the nanocatalyst with a distinctive structure and defects has great potential in industrial application for deep toluene oxidation.